Mining machine



Aug. 28, 1934. A PRATT 1,971,795

MINING MACHINE Filed June 4, 1932 3 Sheets-Sheet 1 QQMML 5. P

Aug. 28, 1934.

c. A. PRATT 1,971,795

MINING MACHINE Filed June 4. 1932 3 Sheets-Sheet 2 Aug. 28, 1934. c. A. PRATT MINING MACHINE Filed une 4. 1952 3 Sheets-Sheet 5 mum km Patented Aug. 28, 1934 Y UNITED STATES P MEN-T iGFFTCfE 1,971,795 'MiNING MACHINE v Charles A.Pratt, Chicago, "Ill.,:a;Ssign0r .to Goodi man Manufacturing Company,0hicago, -Ill.,-a

corporation of iIllinois Application June "4, 1932, SeriaPNo. 615397 21 Claims. (01. 262- 130) This invention relates to improvements in mining machines of the type adapted :to-slide on its bottom on the mine bottom during the cutting operation and has, as one of its principalobjects, to provide a new and improved mining machine of the class described .particularlyadaptedfor operationin thin seams of coal and arranged with a view towards utmost simplicity, compactness, accessibility, and ease and efficiency inoperation. 7

Other objects of my invention will appear from time to time. as this specification proceeds.

My invention may be more clearly understood with reference to the accompanying drawings wherein:

V Figure 1 is atop planview of the device embodying my invention mounted on a self-propelling truck, with parts broken away and in section 'to more clearly show the details thereof;

Figure 2 .is a side elevation of thedevice embodying my invention mounted on ;a se1fprog pelling truck;

Figure 3 isla partial'enlargedfragmentarylongitudinal sectional View: of the device'embodying iii "2.5 :my invention;

Figure 4 is a sectional view takensubstantially -on line L- of Figure 1; a t

Figure 5 is a sectional viewtaken substantially on line 5-5 of Figure 1; and

" Figure 6 is a sectional view'taken substantially on lineG-G of Figure l.

Like numerals refer tto like parts throughout thevarious figures. r

Referring now in particular 'to' the drawings, the embodiment of my invention illustrated-comprises a main frame 10, which'fo'rms a support for the cutting and feeding mechanismQ-"and -a motor 11 detachablysecured to the rearward end of said main frame. A projecting cutter bar I2 49 is supported by and extends; forwardly of said main frame and has a cutter chain lfi guided for movement thereaboutin a usual mannengA feed drum 14 is supported onthe advance side of said main framelfor rotation with "respect thereto about an axis disposed transversely thereof for moving the machine about themine and feeding itinto and along the coal face.

The mining machine istadapt ed to be detach- 5O ably mounted on :a self-propelling truck @15 .for movement about the mine 'on-the mine tracks from working place to working place tintausual manner. Said truckxislof avusualdropiront type andis. supported on track wheels Jlfiwand axlesil'l. Means are provided fordriv'ing -said truck frofn casing 23. =wound field coi1s20which comprise consequent m5 poles therefon and'two1sa1ient poles '21 supported within the split motor casing 23. V .casing :23 is split diagonally vin a vertical plane ..and comprises a forward portion 24 detachably secured to therearward endof thelmainr frame 10 in a suitable manner; as for instance, nutstand ..bolts 25; and a rearward portion 26 detachably .secured to the forward portion .24 by means of .forward portion :24 of the .motor casing 23 .adjacentthe retreating sideof themining machine,

.themining machinemotor ll inia manner which will hereinafter. be .more .fully explained.

Referring now in particular-to the vdetailslof the motor 11 and one of thenovelfeatures of my invention, said motor is herein shownastbeing an electric motor of a high speed type and includes Vanarmature 18.mounted on a verticallydisposed armature shaft 19 enclosed in a split :motor The motor 11-1 is provided with two The 'motor' nuts and bolts in a suitable manner. One of the wound-:fieldcoils 1201 is carried on one side of the 175 while-one of the salient poles 21 is carried ontthe 1 inner side of the forwardiportion '24 forwardly of thezarrnatureshaft 19. The other wounddield coil 20. iszcarried on the rearwardportion .26-of the: motor casing 23 adjacent the advance side ofthe mining machine, andtheother salient pole-21 "of saidmotor, which are larger thanthe salient jgpoles, areypositioned on opposite lateral sides of thearmature "18 and mainframe 10. This arrangement retains=theiminimum dimensions of isaid motor-:withrespect to the length of the machine and effects a machine of a minimum over- .alllength. Thisarrangement also facilitates the 'sremovalwofvthe: rearwardportion .26 of the :motor casing 23 which permitsutmost accessibility to all of the LmOtorparts, and enables-the:mining'ma- ;chine to (be; compactly and efiiciently arranged.

The motorll hasbeenso designed as mm of a minimumverticalr height,. and the motor casing.23

is constructed: as smalitasxpossible commensurate 1mg with'the production-df an efficient powerunitand determines the :height of the machine. Further- .':'more, said motor is of ithe highl speed type which :permits .the v use of a smaller size :amotor .for the same amountof power usually used on 'mining U machines andeaccordingly permits the..construc- -tion of :a lower, more compact machine than is 'tusual inxmining practioe.

- The armature shaft "I9 is supported suitable ball bearingsgindicated by reference character-29, 110

partially recessed Within the armature coils so as to keep down the height of the motor to a minimum and has an armature pinion 27 keyed on the lower end thereof.

An integral bottom portion of the rearward portion 26 of the motor casing 23 is spaced downwardly from the supporting means for the bearing 29 of the armature shaft 19 and forms a slidable support for a portion of said motor. With reference to Figure 1 in particular, it may be seen that the forward edge of the integral bottom portion 30 of the rearward portion 26 of the motor casing 23 is concavely cut away adjacent the longitudinal center line of the machine to permit removal of the armature pinion 27. Said armature pinion may also be removed by splitting said motor casing and removing the armature therefrom.

A bottom plate 31 extends from the main frame 10 adjacent a forward wall thereof. Said forward wall forms a rear wall for a passageway for the cuttings discharged by the cutter chain 13, in a manner which will hereinafter be more fully explained. Said bottom plate extends rearwardly to the integral bottom portion 30 of the rearward portion 26 of the motor casing 23 and is provided with a shouldered portion engaging a corresponding shouldered portion on the bottom portion 30 of the portion 26 of said motor casing. The bottom plate 31 is adapted to be detachably secured to said main frame and forward portion 24 of said motor casing by suitable holding means, such as, cap screws in a suitable manner clearly indicated in Figures 3 and 4. Thus the bottom portion 30 of the rearward portion 26 of said motor casing and bottom plate are so arranged as to permit ready accessibility to all of the parts thereunder and to keep the height of the machine down to a minimum.

Referring now in particular to the drive for the feed operating and cutter chain driving mechanism, and several other of the novel features of my invention, the armature pinion 2'7 meshes with and drives a spur gear 33. Said spur gear is keyed on the lower end of a vertical shaft 34 journaled in suitable ball bearings adjacent the rearward end of the main frame 10. A spur pinion 35 is keyed on the upper end of the vertical shaft 34 and meshes with an idler gear 3'7 journaled on its hub in suitable ball bearings supported in a support member 39 secured to said main frame in a suitable manner. Said idler gear is meshed with and drives a spur gear 40 keyed on the upper end of a vertical shaft 41. Said spur gear is journaled on its hub in suitable ball bearings supported in a transversely extending bearing support 42. A sprocket 43 is freely mounted on the lower end of the vertical shaft 41 and is journaled on its hub in suitable ball bearings supported in said main frame in a usual manner.

The sprocket 43 meshes with and drives the cutter chain 13 and suitable means are provided for operatively connecting said sprocket to the vertical shaft 41 so it may be driven thereby,

which means herein comprise a clutch collar 44 feathered on said vertical shaft. Said clutch collar has jaws 45 depending therefrom which are engageable with jaws 46 extending upwardly from the hub of said sprocket. Said clutch collar is shifted along said vertical shaft by means of suitable clutch operating means which, as herein shown, comprise a clutch fork 4'7 keyed on a transversely extending rock shaft 48 and operatively connected with said clutch collar. Said transversely extending rock shaft is operated by a iand lever 49 disposed rearwardly of the rearward end of the main frame 10. Said hand lever is connected to said rock shaft by suitable crank and link mechanism generally indicated by reference character 50. Thus the cutter chain may be selectively driven by the motor 11 in an obvious manner.

It should also be noted that the cutting mechanism is disposed forwardly of the feeding mechanism and that the cutter chain sprocket 43 and cutter chain 13 are spaced forwardly of the spur gear 33 a distance suflicient to permit the cuttings to be discharged from the retreating side of the machine forwardly of said spur gear. Such an arrangement permits the cutter bar 12 to be disposed above the spur gear 33 so as to intersect the motor 11 and effects a means for enabling the machine to be so arranged as to be of a low over-all height.

Means are provided for deflecting the cuttings to the retreating side of the machine to prevent their accumulation on the advance side thereof, which means herein comprises a suitable cuttings deflector formed by a forward wall 10 of the main frame 10. Said forward wall is curved to conform substantially to the path of the cutter chain 13 so said curved forward wall may cooperate with said cutter chain and aid said cutter chain in expelling the cuttings beyond the retreating side of the machine. Due to the fact that the cuttings deflector is formed from the curved forward wall 10 of the main frame 10, the cuttings passageway formed therefrom is bottomless. This further aids in the disposal of the cuttings in that the cuttings cannot accumulate in the cuttings passageway inasmuch as said cuttings are left behind the machine on the bottom while said machine is moving across the coal face.

Referring now in particular to the feed mechanism, the feed drum 14 is adapted to have a feed rope 51 wound thereon. Said feed rope may extend forwardly from the feed drum 14 around a suitable sheave 52 to a fixed point along the mine wall for feeding the machine therealong during the cutting operation. Said feed rope may also extend rearwardly from said feed drum under a suitable guide sheave 53 at the side of the machine, guide sheave 54 at the advance rearward corner of the machine, and guide sheave 55 adjacent the central portion of the machine for pulling the machine onto the self-propelling truck 15. If desired, said feed rope may extend around guide sheave 55, and a guide sheave 5'7 at the right hand rearward corner of the machine for sumping the machine into the coal face or pulling the machine in a direction opposite to its normal direction of travel.

The feed drum 14 is freely mounted on a suitable boss 58 extending outwardly from the advance wall of the main frame 10. is cut integral with the inner side of said feed drum and is meshed with and driven by a spur pinion 60 keyed on one end of a transversely extending shaft 61. Said transversely extending shaft is adapted to be driven by suitable frictionally controlled gear reduction mechanism which may be of any type, but which is herein preferably shown as being a gear reduction mechanism of the eccentric type, generally indicated by reference character 63.

The gear reduction mechanism 63 includes a drum 64 journaled on its hub in a suitable bearing, support extending upwardly from the main frame 10 and freely mounted on a sleeve 65, which sleeve in turn is freely mounted on the transversely ex-' A spur gear 59 .higher speed.

marines tendin'g shaftlfil. .Aaworm' gear .66 iskeyed-on the :sleeve fifiifonrotating said sleeve andzis :driven :by a worm 67 cut integral withithemvertical. shaft 34 intermediate the :ends thereof.

The frictionally. controlled eccentric agear ."18- ductionlmechanismi63 isof a .well :known type, :so

i will only herein be 'describediinsofar .as is.:necessary to make my invention :clearly understandable. An eccentric69' is formed integral -.-with an end of the sleeve.65 extending within thedrum 64.

.Asuitable ballbearingx'm ismounted onsaid eccentric,.and .aspur gear '71 is mountedon said ball bearing. Said spur. gear in turn meshes with and drives an internalgear '72. cut integral witha cage 68 pjournaled within the drum 64 .for free rotation with respect thereto. A pluralityof lugs from rotation by means of a suitable friction band '75, which engagesthe outer periphery thereof in .a usual manner, rotation of the eccentric 69 will .move the spur gear-.71 in a non-rotatable closed orbital path which in turn will move the internal gear '72 a distance equal to the width of the num- ...ber .of teeth in said spur gear which engage corresponding teeth in said internal gear in a usual manner well known to those skilled in the art. The speed of rotation of saidinternal gear isre- .duced by lessening the pressure of the friction by a hand crank '76 threaded to a. connecting rod "77 which in turn has operative connection with thefricti on band '75 by means of a system of cranks and levers, indicated by reference character 78. Rotation of said hand crank. in one direction will. engage said friction band with said drum, and rotation of said-hand crank in an opposite direction will disengage said friction band from said. drum in an obvious manner.

Suitable clutch means are provided for con- Qnecting the transversely extending shaft 61 with either the sleeve 65 or the internal gear '72 so saidshaft may be driven at eithera high speed ora slower frictionally controlledv speed, which meansherein comprise a clutchsleeve'll) feathered onthe transversely extending shaft 61. Said clutch sleeve extends within the drum 64 and has suitable clutch jaws formed integraltherewith. Said clutch jaws are engageable with clutch jaws 81, formedintegral with the cage 68 .fforthe' internal gear 72 or clutch jaws82,formed integral with the sleeve 65. Thus when the clutch v jaws. 80 are engaged with the clutch jaws 81, the transversely extending shaft 61 and feed drum {14 maybe driven. by the internal gear '72 at a slow frictionally controlled speed, and when said 82, said transversely extendingCshaftand feed drum may be driven from the sleeve 65 at a The clutch sleeve '79 is shifted along the transprise a "clutch collar '83 engaging said clutch sleeve. Said *col'lar isengaged "by a "clutch fork trolled retarding drum 87'having a cable;88 wound thereon. Said retarding drum is freely mounted spur gear 40.

:84. keyed on.ailongitudinally extending :rock shaft .85 .located :beneath :the atransverselysextending shaft :61. Said rockshaft is in turn operatedziby 'means of a suitable handflever86 locatedzatone side :of the :motor. casing .23 srearwardly...oftethe* 80 jmain'pframe 10 adjacent the retreating iside thereof, and a suitable system .or iconnecting cranks and levers in ausualamanner wellknown It should :be noted :that :the drive from the "2.85 motor .11 is: such that :the speed reductionstozthe drum .14 may be effected ina minimuma-mount of space permitting said feed drum -to:be-. selectively driven from said Jmotor at either .a high .speed for :movingathe machine .along the mine :bottom and onto its .truck in .au'sual manner, "or :atza .73 are formed integral with-the spur gear. '71 and lower 'frictionally controlled speed .for summing the cutter bar .12 into thecoalandifeeding :th machineacross the. face of the coal.

Suitable means are provided for controlling and retarding the rearward end of the machine asit is beingsfed along the :coal: face iby the :feed drum-Hand feedrope 5.1, which'meanslisherein preferably shown as being a frictionally commining machine truck from the .motor llyWhiCh 2110 means herein comprise a spurapinion 93.:keyed on the vertical shaft '41 beneath the hub. of the Said spur pinion meshes with and drives'a spurgear 94 keyed on the upper end of vastub shaft 95 journaled intermediate its .5115

ends in a suitable bearing support secured .to the main frame 10. A bevel gearw96 is keyed on the lower endof the stub shaft l95:and:meshes with. and drives abevel gear '97 journaled'on its hubin the mainframe :10 for rotation about 18113120 axis extending .transversely thereof. socket is'formed in the hub of said bevel gear.

A squared Said socketis adapted to be engaged by asquared end 98 of a coupling pin.99 having engagement with a squared inner periphery of a sleeve 100 i journaled in a suitable support extending :up-

.Means are provided to hold the coupling pin 99 in engagement with the squared socket formed in the hub of the bevelgear 9'7, which :means herein comprises a member .103 :pivotally "supi ported adjacent one of its endsto' oneprongof a forked bracket 104 formed integral with the bearingsupport for the sprocket 101. Tho -member :103 is-adapted-to engage the outer (end of the coupling pin 99 intermediate its ends .and 1'40 its opposite end is adapted to be detachably-secured to the opposite prong of the forked bracket 104 by means of a suitable pinin theusual manner. :Said coupling pin may thus be disconnected fromthe bevel gear 97when it .is desiredto uni load the mining machine from its truck or be connected thereto when it is desired to ,.move

the mining-machine about the mine.

1 While'I have herein'shown an'ddescribedone form irrwhich "my" invention may "be embodied, 1550 it will be understood that the construction and arrangement of the parts may be altered without departing from the spirit and scope thereof. Furthermore, I do not wish to be understood as limiting myself to the specific form of construction illustrated herein, excepting as specifically limited in the appended claims.

.- I claim as my invention:

1. In a mining machine, a main frame adapted to slide on its bottom on the mine bottom, a cutter bar having a cutter chain movable thereabout extending forwardly of said main frame, a motor detachably secured to the rearward end of said main frame, said motor determining the height of the machine and having a vertical armature shaft, an armature pinion on the lower end of said armature shaft and means for driving said cutter chain from said motor comprising a spur gear driven by said armature pinion and disposed in a plane so its lower surface is beneath the lowermost extremities of said cutter bar, a vertical shaft driven thereby, and another parallel vertical shaft driven from said first mentioned vertical shaft.

2. A mining machine in accordance with claim 1 wherein a cutter chain drive sprocket is mounted i coaxial with said second mentioned vertical shaft and selectivelyv connectible therewith.

3. In a mining machine, a frame adapted to slide on the mine bottom, a motor detachabiy secured to the rearward end of said frame substantially determining the height of the machine and having a vertical armature shaft having an armature thereon, feed mechanism therefor comprising a feed drum on one side of the machine rotatable about a horizontal transverse axis forwardly of said motor, cutting mechanism therefor comprising a cutter bar projecting forwardly of said main frame having a cutter chain guided for movement thereabout, and means for driving said feed drum and cutter chain from said motor comprising a vertical shaft located rearwardly of said feed drum, another vertical shaft located forwardly of said feed drum, a gear reduction from said motor to said first mentioned vertical shaft disposed beneath said armature and another gear reduction from said first mentioned vertical shaft to said second mentioned vertical shaft disposed adjacent the upper ends of said shafts.

4. A mining machine in accordance with claim 3 wherein a. frictionally controlled gear reduction device is interposed between said first mentioned vertical shaft and said feed drum and driven therefrom by means of a worm on said first mentioned vertical shaft meshing with a worm gear directly connectible with said gear reduction device.

5. A mining machine in accordance with claim 3 wherein a frictionally controlled geared reduc tion device is disposed forwardly of and driven by said first mentioned vertical shaft and driven therefrom by means of a worm on said first mentioned vertical shaft meshing with a worm gear mechanism disposed forwardly of said motor comprising a feed drum rotatable about a horizontal axis disposed transversely of said mining machine and a projecting cutter bar having a cutter chain movable thereabout, and means for driving said feeding and cutting mechanism from said motor comprising a vertical shaft driven from the lower end of said armature shaft at a reduced speed, and another vertical shaft spaced forwardly of said first mentioned vertical shaft and driven from the upper end thereof at a reduced speed.

7. A mining machine in accordance with claim 6 wherein the second mentioned vertical shaft is disposed forwardly of the feed drum and wherein the feed drum is driven from the first mentioned vertical shaft at a relatively high traveling speed or frictionally controlled low feeding speed.

8. A mining machine in accordance with claim 6 wherein the second mentioned vertical shaft is disposed forwardly of the feed drum and has a sprocket thereon selectively connectible therewith for driving the cutter chain.

9. A mining machine in accordance with claim 6 wherein a worm is provided on the first mentioned vertical shaft and a worm gear rotatable about an axis disposed transversely of the mining machine is driven thereby, and wherein a frictionally controlled plural speed gear reduction device is driven by said worm gear and selectively connectible with the feed drum.

10. A mining machine in accordance with claim 6 wherein a worm gear rotatable about an axis disposed transversely of the machine is driven by the first mentioned vertical shaft, wherein a frictionally controlled plural speed gear reduction device is driven by said worm gear and selectively connectible with said feed drum and wherein the second mentioned vertical shaft is disposed forwardly of said feed drum and has a sprocket selectively connectible therewith for driving the cutter chain.

11. In a mining machine, a frame, feeding mechanism therefor comprising a feed drum rotatable about a transverse axis and disposed on one side of said frame, cutting mechanism extending forwardly of said frame including a chain carrying cutter bar, and drive means for said feeding and cutting mechanism comprising a motor including a split casing detachably connectible to the rearward end of said main frame and substantially determining the height of the machine, said motor having an armature rotatable about a vertical axis, a wound field coil carried on onehalf of said motor casing adjacent one side of said machine having a center coincident with a transverse vertical plane coincident with the transverse center line of said motor, a salient pole carried on the same half of said motor casing adjacent the forward end thereof having a center coincident with a longitudinal vertical plane coincident with the longitudinal center line of said motor, a wound field coil carried on the other half of said motor casing adjacent the opposite side of the machine having a center coaxial with the centerv of said first-mentioned wound field coil, and a salient pole carried on the same half of said motor casing adjacent the rearward end of said motor having a center coaxial with the center of said first-mentioned salient pole.

12. A mining machine in accordance with claim 11 wherein the motor casing is split in a vertical plane disposed diagonally of the frame.

13. A mining machine in accordance with claim 11 wherein the armature is provided with an armature shaft and the armature shaft has a pinion keyed on the lower end thereof for driving the feeding and cutting mechanism.

14. A mining machine in accordance with claim 11 wherein means are provided for driving the feeding and cutting mechanism from the motor which comprise an armature shaft, a vertical shaft driven from the lower end thereof and another vertical shaft spaced forwardly of said first mentioned vertical shaft and driven from the upper end of said first-mentioned vertical shaft.

15. In a room and pillar mining machine slidable on its own bottom on the mine bottom, a vertically disposed motor the height of which determines the height of the machine having a motor casing divided in a vertical plane, a vertical shaft for said motor, a main frame disposed forwardly of said motor, cutting and feeding 1nechanism supported by said main frame including a cutter bar having a cutter chain movable thereabout extending forwardly therefrom and intersecting said motor, a cutter chain drive sprocket rotatable about a vertical axis for driving said cutter chain about said cutter bar, a feed drum disposed adjacent one side of said main frame and rotatable about an axis disposed transversely thereof rearwardly of the axis of rotation of said cutter chain sprocket, and means for driving said feeding and cutting mechanism from the lower end of said motor shaft comprising a vertical shaft disposed forwardly of said motor, gear reduction mechanism for driving said shaft from said motor, a worm on said shaft, a worm gear driven thereby and rotatable about an axis disposed transversely of said main frame, frictionally controlled plural speed gear reduction mechanism driven by saidworm, means for selectively connecting said plural speed gear reduction mechanism with said feed drum, and another verti-- cal shaft spaced forwardly of said first mentioned vertical shaft and coaxial with the axis of rotation of said cutter chain sprocket, gear reduction means for driving said second mentioned verttcal shaft from said first mentioned vertical shaft and means for selectively connecting said second mentioned vertical shaft with said cutter chain drive sprocket.

16. In a room and pillar mining machine slidable on its own bottom on the mine bottom, a vertically disposed motor the height of which substantially determines the height of the ma-' chine having a vertical motor shaft with a motor pinion keyed adjacent the lower end thereof, retarding mechanism disposed rearwardly of said motor, and feeding and cutting mechanism disposed forwardly of said motor including a main frame having a cutter bar projecting forwardly therefrom having a cutter chain movable thereabout, and a feed drum disposed at one side of said main frame and rotatable about an axis disposed transversely thereof, means for driving said feed drum from said motor comprising a spur gear driven from said motor pinion having a vertical shaft keyed thereto, means for driving said feed drum from said vertical shaft comprising a frictionally controlled gear reduction devicerotatable about a transversely extending axis disposed forwardly thereof, and means for driving said cutter chain from said vertical shaft comprising a spur gear keyed thereto, an idler gear driven thereby, a spur gear driven by said idler gear, and a vertical shaft driven thereby spaced forwar ly of said feed drum.

1'7. A mining machine in accordance with claim 16 wherein the spur gears for driving the second vertical shaft from the first vertical shaft are keyed on the upper ends of said shafts and the cutter chain driven by a sprocket selectively connectible with said second mentioned shaft.

18. A mining machine in accordance with claim 16 wherein the cutter bar intersects the spur gear on the end of the first mentioned vertical shaft and the second mentioned shaft is spaced from the first mentioned shaft a distance greater than the sum of the radii of the spur gear on the lower end of the first mentioned shaft and the spur gear on the upper end of the second mentioned shaft.

19. In a mining machine, a frame, feeding mechanism therefor comprising a feed drum rotatable about a transverse axis and disposed on one side of said frame, cutting mechanism extending forwardly of said frame including a chain carrying cutter bar, and drive means for said feeding and cutting mechanism comprising a motor including a casing split in a vertical plane disposed diagcnally of the frame and detachably tor casing adjacent the rearward end of said motor.

20. A mining machine in accordance with claim 19, wherein the armature is provided with an armature shaft and wherein said armature shaft has a pinion keyed on the lower end thereof for driving the feeding and cutting mechanism.

21.. A mining machine in accordance with claim 19, wherein means are provided for driving the feeding and cutting mechanism from the motor which comprises an armature shaft, a vertical shaft driven from the lower end thereof and an-- other vertical shaft spaced forwardly of said firstmcntioned vertical shaft and driven from the upper end of said first-mentioned vertical shaft.

CHARLES A. PRATT. 

